Cross-site scripting in HTML Sanitizer - CVE-2026-47345
Published: June 9, 2026
Vulnerability identifier: #VU134018
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2026-47345
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: TYPO3
Affected software:
HTML Sanitizer
HTML Sanitizer
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary script in a victim's browser.
The vulnerability exists due to cross-site scripting in HTML serialization of namespace attributes when processing sanitized HTML content. A remote attacker can supply specially crafted input to execute arbitrary script in a victim's browser.
The issue allows bypassing the cross-site scripting prevention mechanism.
How to mitigate CVE-2026-47345
Install security update from vendor's website.